Tire retreading machine



Jan. 9, 1940.

w. G. RAWLS ET AL I TIRE REIREADING MACHINE;

Filed June 23; 1938 5 Sheets-Sheet 1 In ventors Jan. 9, 1940. w. G.RAWLS r AL 2,185,882

TIRE RETREADING MACHINE Filed June 23, 1938 5 Sheets-Sheet 2 A Inventor:

. /4 WaZtanflawZa 55 Vaug/mfiazfli Attorneys Jan. 9, 1940. w G w s ET AL2,186,882

TIRE RETREADING MAGHINE Filed June 23,- 1938 5 Sheets-Sheet 3 '/Z L EInventors Wanna/2W2; Vazzyiz 72 fZazz/Zi 45 I jzwaolfiam A itorneys1940. w. G. RAWLS El AL 2,186,882

TIRE RETREADING MACHINE Filed June 25," 1938' 5 Sheets-Sheet 4 LvdwInventor;

A ttomeus Jan. 9, 1940. w. ca. RAWLS El AL- 2,186,332

TIRE RETREADING MACHINE Filed June 23, 1938 5 Sheets-Sheet 5' Inventor:

Patented Jan. 9, 1940 wom'rso STATES PATENT. OFFICE TIRE RETREADINGMACHINE Walter G. Rawls and Vaughn Rawls, Lima, Ohio Application June23; 1938, Serial No. 215,497

4 Claims. (01. 18-18) This invention relates to a tire retreadingmachine and has for the primary object the provision of a device of thischaracter which is so constructed as to permit easy and quick re- Atreading of a carcass of a tire mounted on a motor vehicle wheel andinflated to a desired pressure and includes a sectional steam-heatedmatrix with coacting ring members which will support the tire in properposition for the tread ,material which has been previously applied tothe carcass of the tire to be cured in proper shape to give the tire afinished appearance and with a tread capable of providing long and ueflicient service,

Another object of this invention is the provision of convenientlyoperated means for drawing the sections of the matrix together in properalignment to each other and against the tire with a maximum amount ofpressure.

20 A further object of this invention is the provision of an easilyoperated means for separating and raising the sections of the matrixafter the, release of said sections so that the retreaded tire and thevehicle wheel on which it is mounted may be conveniently lifted from thematrix. i

With these and other objects in View, the invention consists in certainnovel features of construction, combination and arrangement of parts tobe hereinafter more fully described and claimed. e

For a complete understanding of my invention, referenceis to be had tothe following description and accompanying drawings, in

which H I Figure 1 is a side elevation illustrating a tire retreadingmachine constructed in accordance with our invention.-

. Figure 2 is a top plan view showing the device.

Figure 3 is ascctional view taken on line3 3 of Figure l showingthelower ring member and the forks employed for lifting and spreading thesections of the matrix.

Figure 4 is. a bottomplan View of the matrix. Figure 5 is a fragmentarytransverse sectional view showing one of the clamping means for thematrix. andztaken on line 5 5 of Figure 2.

Figure 6 is a viewsimilar to Figure 5 showing $6 another one of the;clamping means for the matrix, taken on line 6- 3 of Figure 2.

Figure 7 is a sectional .view'taken on the line I-l of Figure 1. 1

Figure 8 is a fragmentary side elevation illus- 55 trating one 01 theclamping means for the matrix.

Figure 9 is a detail sectional'view taken on the line 9-9 of Figure 3. HFigure 10 is a detail sectional view taken on the line I 0lil of Figure1.

Figure 11 is a detail sectional view taken on ithe line I 1- of Figure3.

Figure 12 is a fragmentary perspective view illustrating one of the feedstems and its coacting feed nut.

Referring in detail to the drawings, the nu-. 10 meral It) indicates} astand consisting of supporting legs ll' on'which is fixed a lower ringmember 12 forming a case or'support for a matrix l3. A ring member l4similarly constructed to the ring memberIZ is arranged to 15 rest uponthe matrix l3 and is so mounted that it may be conveniently moved oil?of the matrix and which will be hereinafter more fully described.

The matrix has its inner face ribbed, as shown at [5, for forming on aretreaded tire a desired non-skid surface. The matrix is composed of aplurality of sections as clearly illustrated in Figure 4 and formed onthe sections are lugs I6 having oppositely beveled faces 11. Some of 26the lugs are located adjacent the ends of the sections while the otherlugs are located substantially intermediate the ends of said sections.

Formed on the lower ring member l2 are arms I8 having upwardly andoutwardly inclined porlo tions 19 terminating in angularly dis-posedclamp attaching portions 20. The upper ring member I4 is equipped witharms 2| similarly shaped to vthearms l8. Yokes 22 are pivoted on theattaching portions 20 of the arms l8 and have 86 threaded thereto stems23 provided with handles,

24 for the convenient rotation thereof. To clamp the matrix between theupper and lower ring members theyokes 22 are brought over the arms 2!and the stems 23 turned thereagainst. The

matrix is then firmly clamped on the support.

The arms 2| depend downwardly and outward-' 1y while the arms l8 extendupwardly and outwardly. The inclination of said arms l8 and 2| is so asto match the beveled faces of certain of the lugs formed on the matrix.

Upper and lower jaws 25 and 2,6 are formed on the upper and lower ringmembers. The jaws 25 include upwardly and outwardly inclined faces 27while the jaws 25 include downwardly 5 and outwardly inclined faces 28;The faces 21 and 28 of the jaws contact the beveled faces of the otherlugs of the matrix. The jaws 25 and 25 when drawn towards each otherhave a wedging action against the matrix for the purpose ll of drawingthe sections of the matrix together with the sections in properalignment with each other. Nuts 29 are pivoted on the jaws 26 and feedshafts 3% thread therein. The feed shafts are equipped with hand wheels3| for the convenient rotation of said shafts in either direction. Thejaws 25 have forked portions 32 to receive the shafts (ill with the hubsof the hand wheels 3% bearing thereagainst so that when the shafts arerotated in one direction the jaws will be drawn in the direction of eachother and when rotated in an opposite direction the jaws will bereleased from each other and also will permit the shafts 30 to be movedout of the forked portions of the jaws 25, thereby permitting the upperring member M to be lifted off of the matrix.

A hinge arm 33 is formed on the upper ring member in and is pivoted on ablock 34 slidably mounted on a supporting rod 35. The block seats on acoil spring 36, the latter being mounted on the supporting rod 35 withone end in engagement with a stop collar 37 secured on the supportingrod 35 with the other end against the block 34. This constructionprovides a hinge structure for the upper ring member on the supportingrod 35 capable of having a limited yieldable sliding movement on saidsupporting rod. A cable 38 is secured on the ring member M opposite thehinge arm 33 and is trained over a pulle 35 carried by the upper end ofthe supporting rod 35 and has secured thereto a weight in for aiding inswinging the upper ring member on its hinge structure.

The matrix 13 or each section thereof has a steam chamber 4i connectedto steam supply pipes a: by flexible pipes 43. The steam chambers iipermit heating of the matrix and thereby cure the tread of the tirearranged in the matrix.

Slotted guide brackets 4 are secured on the lower ring member 12 andslidably support substantially V-shaped push members 45, the upper endsof which contact with the lower wall of the matrix while the apexes ofsaid members are in the form of shanks 415 connected to plate ll by balland socket joints 43. The plate is secured on one end of an operatinglever lli, the latter being pivotally mounted on a fulcrum By depressingthe free end of the lever the push members 45 will slide upwardlyin'iparting upward movement to the matrix to lift the latter off of thelower ring member 12 and the arms and jaws carried thereby. As the 1xlifted upwardly the jaws and arms of the lower ring member bring aboutseparation sections of the matrix, thereby increasing "nal diameter ofthe latter so that a removed from the matrix. The push memoers 55 areprorided with turn buckles 5| whereby the length of said push membersmay be inand decreased for the purpose of regulating the distance inwhich the matrix may be lifted through the depression of the free end ofthe lever 19.

In operation, the upper ring member I4 is swung upwardly on its hingestructure and maintained in its elevated position by the weight 40. Awhich has been prepared with retread is then mounted on a motor vehiclewheel and inflated to a desired pressure. The tire and wheel is thenpositioned in the matrix with the latter in an elevated position bydepressing the free end of the lever 49. After the tire and wheel hasbeen properly positioned in the matrix the operating lever 49 is freedand the upper ring member I4 is swung down- Wardly into engagement withthe tire forcing the tire into proper position within the matrix. Theyokes 22 are then brought over the arms 2i and the stems 23 rotatedagainst the arms 2! drawing the ring member tightly down on the tire andforcing said tire into proper position within the matrix. Also the handwheels 3! after the positioning of the shafts 3D in the forked portions32 of the jaws 25 are rotated. Through the rotation of the shafts 30 andthe stems 23 the sections of the matrix are forced inwardly to decreasethe internal diameter of the matrix and bring said sections in properalignment and in abutting engagement with each other applying onto thetire considerable pressure proper for molding the tread material intoproper shape. Steam is then admitted to the steam chambers for cookingthe retreading material and after the latter has been properly cured thesteam is turned off. The upper ring member M is then released throughthe operation of the hand wheels 3| and crank handles 24. After theupper ring member has been freed from the matrix it is swung upwardlyand the free end of the operating lever is depressed imparting an upwardmovement to the matrix bringing about expansion thereof due to itsengagement with the lower jaws and arms of the lower ring member. Thematrix in its expanded position permits the cured tire and the vehiclewheel to be easily lifted out of the matrix.

It is believed that the foregoing description, when taken in connectionwith the drawings will fully set forth the construction and advantagesof this invention to those skilled in the art to which such a devicerelates, so that further detailed description will not be required.

What is claimed is:

1. A tire retreading machine comprising a supporting structure, a lowerring member carried by said structure, a sectional matrix resting onsaid ring member, means for heating said matrix, an upper ring memberengaging with the matrix, means for hingedly mounting the upper ringmember, lugs formed on the matrix and arranged adjacent the ends of thesections and having oppositely arranged beveled faces, jaws on said ringmembers and having beveled faces to match the beveled faces of the lugs,clamping means for said jaws to cause the latter to coact with the lugsin the contraction of the matrix, and means engageable with the matrixto raise and expand the latter when freed by the jaws, said matrixriding upon the jaws of the lower ring member during its elevation andexpansion.

2. A tire retreading machine comprising a supporting structure, a lowerring member carried by said structure, a sectional matrix resting onsaid ring member, means for heating said matrix, an upper ring memberengaging with the matrix, means for hingedly mounting the upper ringmember, lugs formed on the matrix and arranged adjacent the ends of thesections and having oppositely arranged beveled faces, jaws on said ringmembers and having beveled faces to match the beveled faces of the lugs,clamping means for said jaws to cause the latter to coact with the lugsin the contraction of the matrix, push members slidably connected to thelower ring member and engaging the under face of the matrix, a pivotallymounted operating lever pivotally connected to said push memhere toraise and expand the matrix when freed by the clamping means, saidmatrix riding upon the jaws of the lower ring member during itselevation and expansion. v p

3. A'tire retreading machine comprising a sup porting structure, a lowerring member carried by the supporting structure, a sectional matrixresting on said ring member, an upper ring member engaging with thematrix, lugs formed on the matrix and having oppositely beveled faces,arms formed on said ring members and having portions inclined to matchthe faces of certain of said lugs, jaws on said ring members and havingfaces to match the faces of the other lugs, clamping means for joiningthe arms of the upper and lower ring members, and clamping means forsaid jaws.

4. A tire retreadingmachine comprising a supporting structure, a lowerring member carried by said structure, a sectional matrix resting onsaid ring member, an upper ring member to engage with the matrix, meansfor mount- ,5 ing the upper ring member for movement to- I Ward and fromthe matrix, clamping means for connecting the sections of the matrix,slotted guide plates secured on the lower ring member,

push rods slidable in said plates and engaging 10 the matrix, apivotally mounted operating lever, a plate carried by said lever, andball and socket joints connecting said push rods to said lastnamedplate.

WALTER G. 'RAWLS. 15 VAUGHN RAWLS.

